Study: Herd Immunity Level in UK High Enough to Dodge Second Wave of COVID-19

By Staff, Agencies

Herd immunity in the UK may have reached the required level to shield the population of the country against a second wave of COVID-19, suggests a new study by Oxford University scientists, cited by The Independent.

In the paper, “The impact of host resistance on cumulative mortality and the threshold of herd immunity for SARS-CoV-2,” yet to be peer-reviewed, the researchers hypothesize that some of the population in the UK may already have developed a high level of immunity to the novel coronavirus without previously succumbing to the respiratory disease.

The research suggests that there is evidence showing a degree of resistance to immunity is displayed after exposure to such frequent seasonal coronaviruses as the common cold, while some people might just be naturally more resistant to infection.

The study modelled how interaction between the varying levels of pre-existing immunity could impact the overall “threshold” required to prevent a resurgence of COVID-19.

The results of the study suggested the requisite threshold might be as low as 20 percent.

“It is widely believed that the herd immunity threshold [HIT] required to prevent a resurgence of SARS-CoV-2 is in excess of 50 per cent for any epidemiological setting. Here, we demonstrate that HIT may be greatly reduced if a fraction of the population is unable to transmit the virus due to innate resistance or cross-protection from exposure to seasonal coronaviruses,” write the authors of the study, Jose Lourenco, Francesco Pinotti, Craig Thompson, and Sunetra Gupta, of Oxford University.

The scientists conclude that the results of the research seem to suggest that sufficient herd immunity may already be manifest, substantially mitigating a potential resurgence of the disease.

Models run by Professor of mathematics and statistics at Strathclyde University Gabriela Gomes have shown similar calculations, determining a threshold of under 20 percent needed for herd immunity, writes the outlet.

The research was based on what are known as heterogeneous models – like in the case of the above-mentioned Oxford University study – which operates under the premise that different levels of immunity are rampant within the population.